At BA we manually edit all flights at a set time before departure to pre-allocate passengers travelling with children, passengers who are either Gold or Silver Card holders, passengers with special needs (unaccompanied children, wheelchair passengers, medical requests, but never an exit row!), and sometimes (!) also larger groups of adults. If you book less than 24 hours before departure, this editing service does not apply. BTW, this is not a service officially sold - it is done as a courtesy in the backroom at the airport terminal, so hush.
